Question on Round Gauges & # Hours

[HMBJack]

Question:

Do the pre "fly-by-wire" Yamaha Round Tachometer gauges ACCUMULATE engine hours in the gauge?

Or does the gauge display the # hours from the Engine's ECM?

Example: a round Tachometer is used on 3 different engines for say exactly 100 hours each.
Will the engine hours on the Tachometer show 300 hours or 100 hours?

My understanding is it will show 300 hours. Actual engine hours must come from the YDS connection on the powerhead.

Again - this question is in context of pre "fly-by-wire" gauges.

Please post your thoughts if you know the answer.

Thanks!

[boscoe99]

Never heard of a "fly-by-wire" tachometer.

Fly by wire in airplanes and drive by wire in boats as it relates to throttle and shift control but nothing related to a tachometer.

Yamaha has three types of round tachometers. Analog, conventional multifunction and Command Link.

Analog tachometers don't show any type of hours.

Later conventional multifunction tachometers can show hours but not as reported by the engine to the gauge. Hours are recorded within and retained within the tachometer. Move the tachometer from one motor to another and the hours remain the same.

Command Link round tachometers can show engine hours that are contained within the engines ECU. The ECU tells the CL tachometer what hours to display. Move the ECU to another motor and the hours in that motors ECU will be displayed on the tachometer.

[HMBJack]

Thanks Boscoe99. I guess I meant to say Command Link Vs. fly-by-wire.

In any event, you helped me undertsand better that the later conventional multifunction tachometers record engine hours within the the Tach gauge itself. So, in my example, the Tach will display 300 hours as accumulated from 3 different engines.

If my understanding above is somehow NOT correct, please correct me. Thanks,

[boscoe99]

If, repeat if, you have a later version of a Yamaha conventional multifunction tachometer then the hours are within the tachometer. Does not matter how many engines have been used with that tachometer.

With a Command Link tachometer only the hours from that motors ECU are displayed. Connected to a thousand hour motor a thousand hours will be shown. Connected to a zero time motor zero hours will be shown.

Here are the two tachometer types.

[HMBJack]

My Tachometer is exactly the one on the left - Conventional Tachometer.

So this gauge accumulates hours within the gauge (not from the engine's ECU that it is connected to).

Thanks,